1. Field of the Invention
The present invention generally relates to a steering column assembly.
2. Description of the Related Art
Various steering column assemblies providing telescoping movement are known in the art. Generally, the telescoping steering column assemblies of the prior art include an outer jacket and an inner jacket slideably disposed in the outer jacket. A bushing is disposed inside the outer jacket and the inner jacket slides into the bushing. The bushing provides a frictional force that opposes telescoping movement and that frictional force must be overcome before the steering column may telescope. For the bushing to exert the frictional force, molten plastic is injected into an injection hole defined by the outer jacket at a high pressure. The injection pressure forces the bushing to conform to the shape of the inner jacket, which causes the frictional force to be exerted on the inner jacket. Typically, the frictional force is overcome by either a user pulling or pushing on the steering column or by the steering column telescoping electronically. One such telescoping steering column assembly is shown in U.S. Pat. No. 5,722,300 to Burkhard et al. (the '300 patent). The '300 patent discloses the bushing disposed in the outer jacket, and the inner jacket is disposed in the bushing. Once inserted, molten plastic is injected into the outer jacket to compress the bushing around the inner jacket.
Although telescoping steering column assemblies of the prior art are enjoyed by a wide variety of consumers, the injection pressure of the molten plastic can be difficult to control. Since the frictional force is a function of the injection pressure, the frictional force is difficult to predict and is inconsistent between steering column assemblies. Therefore, a steering column assembly is needed that provides a more consistent frictional force on the inner jacket opposing telescoping movement. Also, a steering column assembly is needed that provides a stronger bond than the molten plastic materials used in the steering column assemblies of the prior art.